1. Field of the Invention
The present invention relates to a secondary battery, and more particularly to a charge and discharge system of a secondary battery and a method of controlling charge and discharge of a secondary battery.
2. Description of the Related Art
In recent years, due to rapid development of electronics, portable electronic devices are being more widely distributed. Rechargeable secondary batteries are widely used as power sources of many of these portable electronic devices.
A conventional rechargeable secondary battery installed in a portable electronic device, such as a portable computer, to be charged and discharged generally includes a bare cell, a charge/discharge switching module, a current detector, a temperature detector, a microprocessor unit (hereinafter referred to as an “MPU”), and an analog front end (hereinafter referred to as an “AFE”). The AFE converts analog information on the secondary battery into digital data and transmits the converted digital data to the MPU. The information on the secondary battery may include a voltage of the bare cell, charge/discharge currents, temperature of the bare cell, and similar information detected from the bare cell, the current detector, the temperature detector, and/or various other diagnostic devices. The MPU determines a status of the secondary battery based on the information transmitted from the AFE, and transmits a corresponding control signal to the AFE. The AFE controls the charge/discharge switching module in accordance with the control signal transmitted from the MPU, so that charge and discharge of the secondary battery is controlled. The MPU of the secondary battery transmits the information on the secondary battery, that is, the converted digital data, to another MPU of a portable electronic device through a system management (SM) bus. The MPU of the portable electronic device controls charging and discharging current using the information on the secondary battery transmitted from the MPU of the secondary battery.